Many of the surfaces found in a modern building, are covered by tiled coverings such as ceramic tiles, slate tiles, decorative glass or mirror tiles or decorative mosaic tiles. The surfaces include floors, ceilings and walls inside the building, as well as floors, walkways, walls, pools and other similar surfaces outside the building. The installation of tiled coverings requires that the underlying substrate be prepared to provide a smooth, level and water-impermeable surface. The proper preparation of the underlying substrate requires significant skill and expertise. The current methods for preparation of the underlying substrate is very time consuming and laborious, increasing the time and cost associated with such installations.
In recent years there has been a significant trend towards homeowners performing maintenance, and even undertaking expansion projects, on their own without employing a professional. Numerous national and regional companies and stores cater to the owner-builders by providing products specifically designed for non-professionals. One area of home maintenance and construction that has largely remained the purview of professionals is the installation of tiled coverings, particularly on vertical surfaces. This is mainly due to the complexity of the traditional methods of installing tiled coverings.
In the current methods of installing tiled coverings, a substrate must be created to support the tiled coverings. There are two principal methods for creating the substrate: building up the underlying substrate or covering the underlying substrate with sheets of structural drywall.
When employing the first method, the preparation of the substrate begins by creating a moisture barrier by lining the area with lightweight building paper or similar material. Next, a combination of wire mesh, leveling sticks, and mortar is laid down over the moisture barrier. The wire mesh is cut into strips of proper size first and then nailed into place over the moisture barrier with special nails that incorporate a paper spacer. The result is that the mesh is stretched taught and spaced away from the moisture barrier. Wet mortar is then applied over the mesh. The mortar must be leveled and uniformly distributed over the entire surface. To assist in this process, one or more wooden strips are temporarily fastened to the surface. These wooden strips act as reference points for leveling the mortar to a uniform thickness. Once the mortar has been leveled, the wooden strips must then be removed and the resulting voids filled in. The final step is to attach the tiled coverings to the wet mortar and leveling the tiles individually to achieve a uniform and level appearance.
The use of structural drywall is an alternative to the procedure described above. Drywall is not as structurally sound as the method previously described, but may be acceptable depending on the type of installation. Water-resistant structural dry wall is generally available in rectangular sheets approximately 4'.times.8' feet in size. To be used as a substrate for installing tiled coverings, structural dry wall is first cut into strips of needed size and shape. The dry wall strips are then fastened to the underlying substrate with fasteners such as nails or screws. The tiled coverings are then attached to the dry wall strips. The main disadvantage of the use of dry wall as substrate is the lack of a moisture barrier. When exposed to moisture, dry wall material will decompose and lose structural integrity, leading to the failure of the installation.
In an attempt to reduce the susceptibility of the dry wall substrate installation to moisture, a concrete-type material has been substituted for the dry wall material using the dry wall installation method previously described. The main disadvantages of the concrete-type material for this type of installation are the high weight and the brittle nature of the material. The high weight of the concrete-type material makes it too heavy for certain applications such as prefabricated housing, mobile homes or marine applications. The brittle nature of the concrete-type material makes it difficult to cut or shape into proper-sized strips.
The installation of tiled coverings that are curved, or of irregular shape, creates significant challenges in the preparation of a substrate. For example, Radius tiles, tiles with a curved upper edge, are commonly used to create a decorative border at the base of a wall. When installing radius tiles, the substrate must be built up sufficiently to accommodate the curved edge of the tile. If the substrate is built up too much, a gap is created between the tile and the underlying substrate below the tile. If, the substrate is not sufficiently built up, the tile will not "sit" properly and the installation will be uneven and unsightly. Similar challenges exist for the installation of curved or irregularly shaped tiles.
The traditional methods for preparing an underlying substrate for the installation of tiled coverings require significant skill to execute properly. They are also time, and labor, intensive and unsuitable for non-professionals.
The difficulty inherent in the preparation of a suitable substrate for installation of tiled coverings has inspired attempts at facilitating certain aspects of the procedure. One such attempt is U.S. Pat. No. 2,852,932 issued in 1958 to S. J. Cable. The Cable '932 patent shows a tile and grouting assembly in which a frame or lattice is provided for retaining ceramic tiles in place. However, the Cable '932 assembly does not eliminate the need for extensive preparation of the substrate but merely eliminates the requirement for grouting between the tiles.
Another attempt in simplification of the installation of tiled coverings is seen in U.S. Pat. No. 3,521,418 issued in 1970 to Bartoloni. The Bartoloni '418 patent shows a pre-finished decorative rigid panel in which tiles are set on a fibrous backing that is impregnated by a plastic resin to bond the tiles to the backing support. However, while the Bartoloni '418 patented panel shows fixing of the tiles in a desired pattern, it may not adequately eliminate the need for preparation of an underlying substrate, especially if the panel is to be installed above a relatively flexible wooden floor and thereafter subjected to localized loading stresses. Also, the Bartoloni '418 patented tile panels do not include means for interlinking adjacent panels or absorbing stresses between adjacent panels.
Another approach can be found in U.S. Pat. No. 4,551,870 issued in 1985 to Presti, Jr. The Presti '870 patent shows a modular form used as a base for building shower stall thresholds. The form is constructed from two opposed former sections formed of light plastic material and adapted to have mortar poured in the space between the former sections. Tiles are attached to the outside of the former section by adhering them to mortar exposed through openings in the former sections. The approach of the Presti '870 patent is limited to constructing shower stall thresholds and the use of pairs of opposed former sections makes the approach unsuitable for direct installation of tiled coverings on flat surfaces. There is also no provision for attaching the former sections directly to the underlying substrate, making the use of mortar a necessary step of each installation.
A further approach to simplifying the installation of tiled coverings appears in U.S. Pat. No. 5,438,809 issued in 1995 to Gernot Ehlrich. The Ehrlich '809 patent teaches a modular flooring system consisting of units comprised of tiles affixed to a backing material and surrounded by a frame. Adjacent units are joined together by elongate strips. This approach, however is limited to installing tiles on horizontal surfaces, such as the floor. This approach relies on the existence of a frame to provide additional support to the tiles and is therefore unsuitable for trim tile installations which consist of one or two rows of tiles installed at the intersection of a wall and the floor or the coping of a swimming pool. Finally, the Ehlrich '809 patent does not address the installation of radius tiles.
Neither the traditional approaches, nor the approaches disclosed by the patents discussed above provide a general purpose product, or method, that can be used for the installation of tiled coverings directly on an unprepared surface.
Furthermore, the traditional approach of using sticks as leveling guides for leveling mortar applied to an underlying substrate is also time consuming and requires great skill to execute. The filling of voids and re-leveling of the mortar after the sticks are removed is a difficult and skill-intensive procedure unsuitable for non-professionals.
Therefore, the need exists for a product that facilitates the preparation of an underlying substrate for the installation of tiled coverings in a manner which reduces the time, labor and expense associated with the installation of tiled coverings and makes it possible for the homeowners who are not professional builders to successful complete tiled covering installation projects.
A further need exists for a product that provides a permanent, embedded leveling guide for wet mortar applied to a surface, which will eliminate the need for the use of temporary guides made from wooden strips.